tables::table::key_by
1)
template <typename... Ts,is_primitive_type... Ps>
template<typename... Ks>
requires ( ( in<Ks,std::tuple<Ts...>> && ... ) && is_tuple_unique<std::tuple<Ks...>> )
inline
ktable<table<std::pair<Ts,Ps>...>,std::tuple<Ks...>>
table<std::pair<Ts,Ps>...>::key_by() const
2)
template <typename... Ts,is_primitive_type... Ps>
template<tuple_ext::is_tuple Ks>
requires ( all_in<Ks,std::tuple<Ts...>> && is_tuple_unique<Ks> )
inline
ktable<table<std::pair<Ts,Ps>...>,Ks>
table<std::pair<Ts,Ps>...>::key_by() const